This is very true. I am weighing the costs/benefits right now regarding an old (1890) bank building in a remote suburb. It's got the charm residential shoppers would love, but the costs to convert would price the units out of the market. On a much larger, more important scale, the situation is worse. I had the opportunity during my career to spend time in offices in the Empire State Building, The Chrysler Building, etc. Even in the late 90s the spaces were small, poorly lit, and lacking the ability to support high speed internet, etc. Now, it must be 10 times worse. There was always plenty of space available even then, because the costs to modernize were too high. Attempting to convert these classic buildings to residential would be financially impossible.